Water conserving toilet

ABSTRACT

Disclosed is a toilet ( 1 ) comprising a toilet bowl ( 2 ), a passage which extends from the base of the toilet bowl to a drain outlet ( 30 ), and a gate ( 100 ), the gate having an open position which allows water within the toilet bowl to flow out of the drain outlet by way of the passage and a closed position in which the gate retains a continuous body of water ( 98 ) within the toilet bowl and a portion of the passage, up to a fill level ( 96 ), the toilet further comprising a divider ( 19 ) arranged to close off the passage above the fill level and to extend below the fill level at a location intermediate the toilet bowl and the water line ( 100 ) where the surface of the continuous body of water contacts the gate, to form a water trap in use when the gate is in the closed position and water is retained up to the fill level. The gate may be a flap operated by a hydraulic actuator ( 36 ), responsive to operation of a manually operable flush control, using mains water as the hydraulic fluid. Water is supplied by a spray ring around the rim of the toilet bowl. The toilet requires less water to flush than toilets including a conventional S-shaped water trap.

FIELD OF THE INVENTION

The present invention relates to the field of water conserving toilets.

BACKGROUND TO THE INVENTION

At the present time, one third or more of the water consumed by manyhouseholds is used to flush conventional toilets, which have a cisternand S-shaped water trap. In conventional toilets, only a small fractionof the flush water is required to cleanse the toilet bowl and themajority of the flush water is employed to provide hydraulic energysufficient to impart kinetic energy to the water already present in thetoilet bowl and to carry solids through the S-shaped water trap.

Many innovations have been proposed to control the amount of flush waterdispensed by a cistern. However, the kinetic energy required to carrysolids through an S-shaped water trap limits the extent to which it ispossible to conserve water in this way. It is known to provide a toilet,such as a chemical toilet, in which the S-shaped water trap is dispensedwith and an aperture with a simple flap is provided at the base of thetoilet bowl to provide a passage for solids to be evacuated verticallydownwards from the base of the bowl. This avoids the requirement for ahigh volume of flush water to be provided to force solids through anS-shaped water trap. However, unless the flap is gas tight, gas willleak from the drain outlet to the surrounding atmosphere. It isdifficult to provide a reliable gas tight seal around a moveable flap,particularly as the flap may be soiled in use, and particularly where itis desirable to retain a body of water within the toilet bowl prior toflushing. Furthermore, a toilet of this type could not be fitted intothe toilet fixture which is currently typical in the UK, in which thedrain outlet mates with a pipe, the interior base of which is below thebase of the toilet bowl, extending backwards from the toilet, abovefloor level.

The present invention aims to provide an improved water conservingtoilet, which requires less water to flush than conventional toilets andwhich resists the passage of gas from the drain outlet to thesurrounding atmosphere. Some embodiments of the invention employ acost-effective automatic flush mechanism which does not require anelectricity supply. Some embodiments of the invention provide a waterconserving toilet which can be fitted to toilet fitments in which thedrain outlet mates with a pipe, the interior base of which is below thebase of the toilet bowl, extending backwards from the toilet, abovefloor level; however, this will only be applicable in countries whichuse this toilet drain configuration.

SUMMARY OF THE INVENTION

Within this specification and the appended claims, references todirections, such as “horizontal”, “downwards” etc. refer to theequivalent direction in an assembled and fitted toilet. Words such as“rearwards” and “behind” refer to the direction opposite to thedirection in which a user of an assembled and fitted toilet would facewhile sitting on the toilet.

According to a first aspect of the present invention there is provided atoilet comprising a toilet bowl, a passage which extends from the baseof the toilet bowl to a drain outlet, and a gate, the gate having anopen position which allows water within the toilet bowl to flow out ofthe drain outlet by way of the passage and a closed position in whichthe gate retains a continuous body of water within the toilet bowl and aportion of the passage, up to a fill level, the toilet furthercomprising a divider arranged to close off the passage above the filllevel and to extend below the fill level at a location intermediate thetoilet bowl and the water line where the surface of the continuous bodyof water contacts the gate, to form a water trap in use when the gate isin the closed position and water is retained up to the fill level.

As the passage extends from the base of the toilet bowl and the gateallows water within the toilet bowl to flow out of the drain outlet whenthe gate is open, there is no need for the substantial volume of flushwater which functions to carry solids within the toilet bowl through theS-shaped water trap of a conventional toilet during flushing.

Nevertheless, the provision of a divider which is arranged to close offthe passage above the fill level and to extend below the fill level,into the continuous body of water in use, to form a water trap, preventsunpleasantly smelling gas from diffusing from the drain outlet to thetoilet bowl in the gas phase. The toilet should preferably be formed andarranged so that there is no other path for gas from the drain outlet todiffuse into the surrounding atmosphere in the gas phase.

Preferably, the gate comprises a flap having a hinged base. The hingedbase is typically attached to the interior base of the passage. Thehinged base may comprise a jointed or flexible hinge, for example, theflap may include a flexible portion which functions as a hinge, flexiblyattaching the flap to the interior base of the passage. Typically, inthe open position, the flap extends horizontally, or horizontallydownwards, from the hinged base, towards the drain outlet, to allowwater to flow from the toilet bowl through the passage over the gate tothe drain outlet. Preferably, in the closed position, the flap extendsgenerally vertically from the hinged base. The flap is preferablylocated within the passage and the divider is preferably locatedentirely intermediate the flap and the toilet bowl. However, the hingedbase of the flap may be located underneath the divider, or within thetoilet bowl, or between the toilet bowl and the divider, and extendsunder the divider towards the drain outlet.

Where the gate comprises a flap, the gate preferably further comprisesflexible sealing members which extend from the flap to the adjacentwalls of the passage and which flex in use as the flap moves between theopen and closed positions. This arrangement has the advantage that thereneed not be a sliding contact between the side walls of the flap and thewalls of the passage. The flexible sealing members are typically insealing engagement with the walls of the passage at an orientation whichis intermediate the orientation which the flap adopts in the openposition and the orientation which the flap adopts in the closedposition, for example, the join between the flexible sealing members andthe interior of the passage may extend from the hinged base of the flapat an angle of between 30° and 75°, and preferably around 45°, from thehorizontal, towards the drain outlet.

The flexible sealing members may be integral with the flap. The flexiblesealing members may be elastic. The flexible sealing members maycomprise folds. The flap and flexible sealing members may be formed asan integral member comprising one or more folds. In a preferredembodiment, the gate comprises a flap and flexible sealing members oneither side of the flap, wherein the flap and flexible sealing memberare formed as an integral piece of material, such as a folded sheet ofelastomeric material. Preferably, the base and sides of the gate areintegral with, or extend into, the wall of the passage. As discussedfurther below, the gate (e.g. flap and flexible sealing members) mayextend into a recess between passage sections.

However, alternative gates may be employed. For example, the gate maycomprise a flap having a generally vertical hinge, or a wall whichextends above the fill level in the closed position but does not extendabove the base of the passage in the open position, to allow water toflow from the toilet bowl through the passage to the drain outlet.

Typically, the toilet bowl and passage are formed and arranged toprovide a continuous downhill path for water to flow from the toiletbowl through the passage to the drain outlet when the gate is in theopen position. Typically, the toilet bowl and passage are formed andarranged to provide a continuous path for water to flow from the toiletbowl to the drain outlet at a mean angle of between 5° and 20° below thehorizontal.

The drain outlet may be provided behind the toilet below the base of thetoilet bowl and above a floor contacting base of the toilet. The drainoutlet may comprise a section of pipe facing generally rearwards fromthe toilet. Thus, the toilet can be fitted to the toilet fitments whichare in common use in the UK and some other territories in which a soilpipe is provided which extends from behind the toilet, below the toiletbowl and above floor level. However, the drain outlet may be provided ina different configuration for use with different toilet fittingsappropriate to the market where the toilet is to be sold.

Preferably, the toilet comprises a bowl portion and an adaptor pipeportion, wherein the bowl portion comprises the toilet bowl and divider,wherein the passage is formed at least in part by the adaptor pipeportion and is typically also formed at least in part by a passagesection of the bowl portion which extends from the divider. Typically,the adaptor pipe portion and passage section of the bowl portion areattachable in an abutting relationship. Typically also, the adaptor pipeportion is attachable to a soil pipe in an abutting relationship. Thisallows for modular construction of the toilet. The bowl portion andadaptor pipe portion may be detachable to facilitate repair and/ormaintenance of the gate.

Preferably, the adaptor pipe portion and bowl portion (typically thepassage section of the bowl portion) are sealable together bycooperating flanges, which typically extend rearwards and upwards, forexample at an angle of around 45° to the horizontal.

Preferably, the gate is arranged to be fitted between the adaptor pipeportion and the bowl portion. For example, either or both of the bowlportion abutting end of the adaptor pipe portion and the adaptor pipeportion abutting end of the bowl portion may comprise a recess forreceiving the gate. The base and sides of the gate may be made from anelastic (e.g. elastomeric) material formed and arranged to locate withinthe recess. Accordingly, the base and sides of the gate are typicallysealed into the said recess in an assembled toilet. In a preferredembodiment, the gate comprises a said flap and flexible sealing membersformed of an elastomeric material and arranged to extend into and besealed within said recess.

The gate (e.g. a flap and flexible sealing members) is typically madefrom an elastomeric material such as silicon rubber or a flexibleplastics material such as flexible polyvinyl chloride, acrylonitrilebutadiene styrene or polyethylene.

Typically, the passage comprises a first passage region extending underthe divider and a second passage region extending from the dividertowards the drain outlet, wherein the ceiling of the second passageregion is higher than the fill level so that there is an air space abovethe body of water in the second passage region, extending up to thedivider, when the gate is closed and the toilet is filled with water upto the fill level.

The gate (e.g. a flap) may contact the divider on the side of thedivider towards the drain outlet. In this case, the gate preferablycontacts the divider below the fill level and extends above the filllevel on the side of the divider towards the drain outlet such thatthere is a water-filled gap between the divider and the water line wherethe surface of the continuous body of water contacts the gate.

A benefit of the claimed arrangement is that the gate need not form agas tight seal between the drain outlet and the toilet bowl. This isadvantageous as it is difficult to form a gas tight seal which will bereliable in the long term, particular if the gate may be fouled in use.

Typically, the gate extends above the fill level but below the ceilingof the second passage region when the gate is in the closed position.Accordingly, a continuous air space may extend from the drain outlet tothe divider, above the retained water, when the gate is closed and thetoilet bowl is filled up to the fill level.

The divider is preferably fixed. For example, the divider may beintegral to the toilet bowl. Typically, the toilet bowl and divider, andoptionally the passage, or a portion of the passage, are an integrated(preferably monolithic) unit formed, for example, from a plasticsmaterial or preferably a ceramic. The divider may be demountable tofacilitate replacement.

The surface of the divider which faces the toilet bowl typically formspart of the surface of the toilet bowl, although the divider could berecessed from the toilet bowl, within the passage. Typically, thevertical distance between the base of the divider and the base of thepassage, underneath the divider, is at least 5 cm to facilitate theoutflow of solids material.

The base of the divider is typically rounded to facilitate cleaning andthe flow of water underneath the divider.

The toilet bowl has a rim. A water conduit may be provided around theperiphery of the toilet bowl, near the rim, the water conduit comprisinga plurality of apertures through which water is directed down the sidesof the bowl to rinse the sides of the toilet bowl for a period of timeand refill the toilet bowl up to the fill level when the toilet isflushed. A removable conduit may be provided in which case the toiletcomprises a water outlet for supplying flush water to a removableconduit, and the toilet may be provided as a part of a kit furthercomprising one or more removable, generally ring-shaped, water conduitshaving a plurality of apertures around the ring.

The gate should be movable from the closed position to the open positionresponsive to operation of a manually operable flush control, such as aflush button or handle. Preferably, a flush mechanism is operable tocause the gate to move from the closed position to the open position fora first period of time following operation of a manually operable flushcontrol and then to cause (e.g. allow) the gate to move from the openposition to the closed position. Preferably also, the flush mechanism isoperable to cause water to flow into the toilet bowl, for example, byway of said apertures in said water conduit, for a second period oftime, which is longer than the first period of time. The flush mechanismmay be operable to cause water to flow into the toilet bowl, forexample, by way of said apertures, for a second period of time, which islonger than the first period of time, by causing water to flow into thetoilet bowl until a water level sensor indicates that the water levelhas reached the fill level.

The flush mechanism may be mechanical. For example, a mechanical linkagemay be provided between the manually operable flush control and thegate.

The flush mechanism may comprise a hydraulic actuator operable to movethe gate between the closed position and the open position, and ahydraulic line operably linked to the manually operable flush controland the hydraulic actuator. Accordingly, the flush mechanism preferablycomprises a pressurisable chamber in fluid communication with thehydraulic line, the pressure within which is changeable by operation ofthe manually operable flush control. Preferably, mains water is used asthe hydraulic fluid to transmit hydrostatic force to the hydraulicactuator. This is advantageous as the toilet anyway requires a watersupply and further water can be supplied in the event of any minorinternal leakage.

Preferably, the flush mechanism is operable to increase the pressurewithin the pressurisable chamber in response to manual operation of theflush control. Preferably also, the pressurisable chamber is a chamberwithin a piston cylinder and the manually operable flush control isoperably linked to the piston cylinder. For example, the flush mechanismmay comprise a flush rod having first and second ends, the first end ofwhich is connected to a flush button by way of a biasing member (e.g. aspring), and the second end of which is attached to or forms a pistonwithin a piston cylinder.

Preferably, the hydraulic actuator is a piston cylinder, for example apiston cylinder comprising a piston which extends from the pistoncylinder and is mechanically linked to the gate. Where the gate is aflap, the piston cylinder preferably comprises a piston driving chamberin fluid communication with the hydraulic line, and a pistonmechanically linked to a strut extending to the underside of the gate,the piston cylinder further comprising a biasing member which acts toreduce the volume of the piston driving chamber.

The hydraulic actuator may comprise an inflatable chamber in fluidcommunication with the hydraulic line, which inflatable chamber has aninflated state and a deflated state, wherein the gate is mechanicallylinked to the inflatable chamber so that the gate adopts the openposition or the closed position when the inflatable chamber is in theinflated state and the gate adopts the closed position or open positionrespectively when the inflatable chamber is in the deflated state.

The hydraulic actuator may be integral to the gate. For example, wherethe hydraulic actuator comprises an inflatable chamber in fluidcommunication with the hydraulic line, the inflatable chamber may beintegral to the gate and the gate may be formed and arranged so that thegate adopts the closed position or the open position when the inflatablechamber is in the inflated state and the gate adopts the open positionor the closed position respectively when the inflatable chamber is inthe deflated state.”

Preferably, a pressure equalising device is provided which is operableto restore pressure in the hydraulic actuator (e.g. within the pistondriving chamber where relevant) to an equilibrium pressure a period oftime after operation of the manually operable flush control. Preferably,the pressure equalising device is formed and arranged so that pressurewithin the hydraulic actuator either does not change, or changes onlyslowly, for a period of time and then returns rapidly to equilibrium toreturn the gate rapidly to the closed position. Typically, the flushmechanism is arranged so that operation of the manually operable flushcontrol increases the pressure within the pressurisable chamber, and thepressure equalising device is operable to cause pressure to decreaserapidly to equilibrium pressure a period of time after operation of themanually operable flush control, in order to return the gate to theclosed position.

As the hydraulic actuator is operably linked to the pressurisablechamber via the hydraulic line, the pressure equalising device may be influid communication with one or more of the hydraulic actuator (e.g. thepiston driving chamber, where relevant), the hydraulic line and thepressurisable chamber. The pressure equalising device may comprise aslowly leaking member, such as a member which is porous or has one ormore apertures therethrough. In a preferred embodiment, thepressurisable chamber is formed in a piston cylinder between a firstpiston, which is operably linked to the manually operable flush control,and a second piston, which is biased to compress the pressurisablechamber, wherein the second piston divides the pressurisable chamberfrom a further chamber within the piston cylinder, wherein the furtherchamber comprises one or more orifices through which water can slowlyleak in use. The second piston may be biased to occlude a pressureequalising port of the piston cylinder, and moveable slowly as a resultof water passing slowly out of the further chamber, enabling the secondpiston to move slowly to a position where it brings the pressurisablechamber into fluid communication with the pressure equalising port, toenable pressure within the pressurisable chamber to rapidly return tothe equilibrium pressure.

Preferably, the flush mechanism is operably linked to a valve which isoperable for a period of time responsive to the operation of the flushcontrol to supply water to the toilet bowl, for example through the saidwater conduit or replaceable spray member. The manually operable flushcontrol may be arranged to open the valve responsive to a drop in thewater level within the toilet bowl or passage. Preferably, the flushmechanism is arranged to open the valve by a mechanical arrangementresponsive to manual operation of the manually operable flush controland to close the valve responsive to detection by a water level sensorthat the level of water within the toilet bowl or passage has reached afill level. The level sensor may comprise a float. The flush mechanismmay comprise a lever arm having first and second ends with a pivottherebetween, the first end being mechanically attached to the float(e.g. by a connecting rod) and the second end being mechanicallyattached to the valve (e.g. by a connecting rod). Where the flushmechanism comprises a said flush rod, the flush rod may be mechanicallyconnected to the said lever arm, for example, by way of a toggle hookwhich demountably engages with a spigot which is attached to the saidlever arm intermediate the first end and the pivot, to open the valveresponsive to manual operation of the flush control.

According to a second aspect of the present invention there is provideda toilet comprising a toilet bowl, and a passage which extends from thebase of the toilet bowl to an outlet located to the rear of the toilet,the toilet further comprising a divider arranged to close off an upperportion of the passage between the toilet bowl and outlet.

The outlet may be adapted for direct attachment to a soil pipe, or forattachment to an end of an adaptor pipe, for indirectly attaching thetoilet to a soil pipe.

The toilet may be provided as a part of a kit further comprising anadaptor pipe having a gate attached thereto, or a fitting for receivinga gate (and preferably also a gate receivable in said fitting), the kitbeing assemblable to form a toilet according to the first aspect of theinvention.

Preferably, the outlet and the said end of the said adaptor pipe areadapted to join in an abutting relationship and either or both of theoutlet and the said end of the said adaptor pipe comprise a recess forreceiving and sealedly retaining a gate.

The toilet may comprise an aperture extending rearwards from the toiletbowl under the divider into a passage, the passage having an interiorsurface which extends higher than the uppermost point of the aperture.

Typically, the toilet bowl, passage and divider are formed as anintegrated (preferably monolithic) unit.

Preferably, the outlet is located below the base of the toilet bowl,above a floor contacting base of the toilet, rearwards of the toiletbowl. This enables the toilet to be fitted to a toilet fitment having asoil pipe extending from the rear of the toilet, above floor level.

Preferred features of the toilet and gate correspond to those discussedabove in relation to the first aspect of the invention.

DESCRIPTION OF THE DRAWINGS

An example embodiment of the present invention will now be illustratedwith reference to the following Figures in which:

FIG. 1 is a sectional view of a toilet according to the presentinvention, while filled to a fill level;

FIG. 2 is a schematic diagram of a flush control mechanism for thetoilet of FIG. 1,

FIG. 3 is a cross-section through an adaptor pipe with a fitted flap inthe raised position;

FIG. 4 is a cross-section through a bowl portion;

FIG. 5 is a cross-section through the adaptor pipe of FIG. 3 with afitted flap in the lowered position;

FIG. 6 is a perspective view of the passage of a toilet according toFIG. 1 cut away to show the gate in the raised (closed) position; and

FIG. 7 is a perspective view of the passage of a toilet according toFIG. 1 cut away to show the gate in the lowered (open) position.

DETAILED DESCRIPTION OF AN EXAMPLE EMBODIMENT

With reference to FIG. 1, a toilet 1 comprises a ceramic unit 2 and rearhousing 4, which has a manually operable flush button 6 (functioning asthe flush control) mounted thereon, and encloses the majority of a flushcontrol mechanism which is described further below. The ceramic unit isshaped to define a toilet bowl 8 having an interior base 10, interiorwall 12 and rim 14 with an overhanging peripheral lip 16 which lipretains a spray ring 18, the spray ring being formed from an injectionmoulded plastics material and comprising a plurality of apertures (notshown).

The interior wall of the ceramic unit includes a baffle 19 (functioningas the divider) which separates the toilet bowl from a first pipesection 20. An aperture 22 extends under the baffle into the first pipesection to allow the passage of water and solids from the toilet bowlinto the first pipe section in use. The first pipe section is sealedlyattached to a second pipe section 24 by cooperating flange members 26,28 on the first and second pipe sections, respectively. The cooperatingflange members extend rearwards and upwards at an angle of around 45° tothe horizontal. The second pipe section extends to a drain outlet 30and, together with the first pipe section, forms a passage extendingfrom the base of the toilet bowl to the drain outlet.

Within the passage, a flap 32 (functioning as the gate) is locatedwithin the passage and is pivotably attached to the base of the passageby a hinge 34 and sealedly attached to the passage walls to either sideof the flap by flexible sealing members 35, illustrated in FIG. 3. Theflap is deployable from a raised position (functioning as the closedposition), in which the flap extends generally vertically to a loweredposition (functioning as the open position), in which the flap extendshorizontally rearwards and slightly downwards, by a flap actuating slavecylinder 36 (functioning as the hydraulic actuator). The slave cylinderincludes a piston 38 (shown in FIG. 2) having a piston rod 40 whichextends out of the cylinder to a crosshead 42 from which a strut 44extends to a hinge 46 on the rear surface of the flap. The piston isbiased by a spring 48 within the cylinder so that, by default, the flapis maintained in the raised position.

FIG. 2 is a schematic diagram of components of a flush controlmechanism, located at least partially within the rear housing. The flushbutton is connected via a spring 50 to a flush rod 52. The spring biasesthe flush button upwards and the flush button is pressable downwards toa position limited by an endstop 54. The flush rod extends downwards andits lower extremity functions as a first piston 56 within a hydraulicmaster cylinder 58, the hydraulic master cylinder further comprising asecond piston 60 with a pressurisable chamber defined between the firstand second piston cylinders. The master cylinder has a slave pistondriving port 62, located between the first and second pistons in fluidcommunication with a hydraulic line 64; a leak controlling port 66located at the base of the cylinder, in fluid communication with anunpressurised water reservoir 68; and a discharge port 70 which isoccluded by the second piston when the flush control mechanism is in itsrest state prior to use. The second piston is biased upwards by a spring74 located within a further chamber which is divided from thepressurisable chamber by the second piston and which is in fluidcommunication with the leak controlling port. The hydraulic line extendsto and is in fluid communication with a piston driving chamber 76 of theslave cylinder.

The flush rod is pivotably mounted to a toggle hook 78 which engages ona spigot 80 located on a lever arm 82, the said lever arm having a pivot84. The lever arm is linked by a connecting rod 86 extending from thefirst end, on the same side of the pivot as the spigot, to a float 88(functioning as a water level sensor) located within a float chamber andin sensing communication with water within the passage by means of ahydraulic line 89 which extends to a sensing port in fluid communicationwith the bottom of the toilet bowl, in the region of the flap. Thebottom of the float chamber is level with the sensing port, so that thewater level in the float chamber is the same as the water level in thetoilet bowl and passage.

The second end of the lever arm is mechanically linked to a fill valve90 which is openable to allow water to pass from the main water supplythrough the fill valve inlet 92 to the fill valve outlet 94 and theninto the spray ring and out through the apertures located around thespray ring and down the sides of the toilet bowl. The fill valveincludes a sealed bore with a ferrous slug therein which, when pulledupwards when the second end of the level arm is raised, opens amagnetically actuated pilot allowing water to flow from the inlet of thefill valve to the outlet. A pipe interrupter valve 95 is providedbetween the fill valve outlet and the spray ring to prevent siphonageand/or backflow by creating an open vent to the surrounding atmosphere.

With reference to FIGS. 3 and 4, the ceramic unit, baffle and the firstpipe section (together functioning as the bowl portion) are typicallyformed as a monolithic unit 96, illustrated in FIG. 4. The second pipesection (functioning as the adaptor pipe portion) includes a first end98 which is adapted to be attached to a soil pipe and so function as thedrain outlet, and a second end 100 (functioning as the bowl portionabutting end of the adaptor pipe portion) which includes a shallowrecess 102.

In order to assemble the toilet, the second pipe section is plumbed to asoil pipe. The flap actuating slave cylinder and hydraulic line arefitted to the second pipe section. A piece of elastomeric materialcomprising both the flap and flexible sealing members, and including anumber of flexible hinges, is located in the shallow recess. The gateinitially stands proud of the recess. The ceramic unit is then fitted tothe second pipe section by abutting the second end of the second pipesection and the open end of the first pipe section (which functions asthe pipe adaptor abutting end of the bowl portion). The flanges aresealed together, for example with bolts. The edges of the piece ofelastomeric material, which extend into the shallow recess, arecompressed, forming a seal between the flap and the passage.

The ceramic unit includes a ground engaging base (not shown) whichdefines the height at which the first pipe section extends above thefloor onto which the toilet is fitted. The rear housing is mountedbehind and above the ceramic unit with the float mechanically linked tothe first end of the lever arm and the slave cylinder connected to thehydraulic line. The spray ring may, for example, be formed as a siliconrubber moulding having an inlet for receiving water from the fill valve.The master cylinder, hydraulic line and slave cylinder may be formed asan integral unit, e.g. as a single moulding from a plastics material.

Between flushes, the flap adopts the raised position illustrated inFIGS. 3 and 6, and the toilet bowl remains filled up to a fill level 104with a continuous body of water 106 which extends from the toilet bowlinto the passage, to the flap, up to a water line 108 on the surface ofthe flap. A gas space 110 above the water line, within the passage, isin gaseous communication with the drain outlet and so will accumulateunpleasantly smelling gases, from the drain. The baffle depends from theroof of the passage into the continuous body of water, to below the filllevel, thereby forming a water trap separating the gas space from thetoilet bowl. Accordingly, provided that the passage has been sealedcorrectly to the drain outlet, gases from the drain cannot penetrate thesurrounding atmosphere except by dissolving in the body of water andevaporating from within the toilet bowl.

When the flush button is depressed by a user, the button engages withthe endstop, and the manual action of the user compresses the spring.The spring exerts a downwards force on the flush rod and thus the firstpiston. Water in the pressurisable chamber within the master cylinder isthereby pressurised and displaced into the hydraulic line. Water isconcomitantly displaced from the hydraulic line into the piston drivingchamber of the slave cylinder where it moves the piston against thebiasing spring, retracting the strut and causing the flap to pivotaround its hinge from the raised position to the lowered position,illustrated in FIGS. 5 and 7. As a result, the continuous body of waterdrains through the passage, over the gate and out of the drain outlet.The aperture under the baffle is dimensioned to provide sufficient sizefor solid waste to flow out of the toilet bowl and along the passage. Asthe body of water drains through the passage and the depth of waterwithin the toilet bowl and passage drops to near zero, the float alsodrops within the float chamber.

The downward motion of the flush rod simultaneously causes the togglehook to pull down on the spigot, thereby pulling the first end of thelever arm down and the second end of the lever arm up, opening the fillvalve and allowing water to flow from the mains water supply, throughthe fill valve, to the spray ring. Water flows from the spray ring downaround the periphery of the toilet bowl. Because the flap and bafflearrangement does not require water within a fixed water trap to bedisplaced, the water which flows down from the spray ring is notrequired to provide fluid kinetic energy. Water is required only toclean and refill the toilet bowl.

As the flush rod continues downwards, the toggle hook goes over centreand disengages from the spigot, allowing movement of the level arm to bedisengaged from movement of the flush rod.

As a result of the pressure within the pressurisable chamber, waterflows slowly out of the master cylinder through the leak controllingport. The second piston gradually moves downwards at a rate which can beaccurately controlled by appropriate selection of the diameter of theleak controlling port and the spring modulus of the various springs. Thesimultaneous gradual loss of pressure is not sufficient to significantlyaffect the slave cylinder and the position of the flap. However, oncethe second piston moves sufficiently far towards the base of the mastercylinder, it uncovers the discharge port, through which water in thepressurisable chamber rapidly flows, causing sudden depressurisation ofthe pressurisable chamber of the master cylinder, the hydraulic line andthe piston driving chamber of the slave cylinder. Accordingly, as aresult of the action of the biasing spring within the slave cylinder,the flap returns to the raised position. Water flows into the toiletbowl through the apertures in the spray ring and the water level withinthe bowl and passage rises. The float rises with the water level in thepassage and, once the water level has reached a fill level, the risingfloat raises the first end of the lever arm and pushes down the secondend of the lever arm to cut off the water flow to the spray ring.

Once the user has released the flush button, the flush rod rises, thetoggle hook reengages, the second piston rises back up to again coverthe discharge port, and the master cylinder refills leaving the toiletready for the next flush.

A user can select a partial flush by releasing the flush button beforethe entire continuous body of water has flowed to the drain outlet,allowing the flap to rise. In this case, water will continue to flowinto the bowl through the spray ring until the water level sensingmechanism determines that the fill level has been reached.

Accordingly, the toilet requires less water than a conventional toiletwhich includes an S-shaped water trap and requires a significant volumeof water to provide kinetic energy to displace water within the toiletbowl through the water trap. Nevertheless, the water trap formed in useby the flap and baffle prevents gas from passing from the drain outletinto the surrounding atmosphere while the toilet is filled with water upto the fill level. Thus, the water within the passage forms a gas sealand so the flap itself can retain water within the bowl withoutrequiring to form a gas tight seal around its entire periphery.

The toilet can be fitted to a conventional toilet fitting in which adrain pipe is provided extending rearwards from the toilet, below thetoilet bowl and above floor level. The flush button and generalconfiguration of the toilet is similar to conventional toilets whichfacilitates acceptance of the product by the general public.

As the flap moves from the raised position to the lowered position andvice versa, the flexible hinges flex. As the flexible sealing membersare fixed to the passage walls, a reliable seal is readily formedbetween the flap and the passage. It would be difficult to obtain areliable seal if the edges of the flap had to slide against the sides ofthe passage, and it would be necessary to use a passage with anon-circular cross-section. As the flexible sealing members are sealedto the passage walls at an angle of 45° to the horizontal, which isapproximately half way between the orientation of the flap in the raisedposition and the orientation of the flap in the lowered position, theforce on the flexible sealing members and the surface area of theflexible sealing members are minimised. In some embodiments, the secondpipe section is demountable from the first pipe section and drain outletto facilitate replacement of the flap.

The spray ring can be removed and replaced readily. Otherwise, manualintervention is not required except for ongoing cleaning. Whererequired, the fill level can be adjusted by varying the mechanicalconnection between the float and the first end of the lever rod.

One skilled in the art will appreciate that the flush mechanism, whichis operable to open the gate for a period of time and to introduce waterto the toilet bowl for a longer period of time, may readily be replacedby alternative mechanisms which have the same effects, including purelymechanical mechanisms and/or electrical mechanisms.

In alternative embodiments, the flap may be replaced by an alternativegate, such as a gate having two or more parts; one or more gate portionswith vertical hinges; a gate comprising a wall which is raised orlowered to allow water to flow to the drain outlet in the open position;and so forth. Where the gate is a flap with a hinge along the base, thehinge may be located underneath the divider or even within the toiletbowl. In this case, the invention envisages that the top of the flapwould extend rearwards of the divider so that there is at least a smallbody of water between where the water line contacts the flap and thedivider, so that the body of water forms a water trap.

Although the divider has been illustrated as a fixed, integral part of atoilet bowl, the divider may take the form a demountable baffle, amoveable baffle which is, for example, raised as part of the flushmechanism and/or a baffle which is recessed within the passage. Thedivider may also comprise an elongate passage portion.

Further modifications and variations may be made within the scope of theinvention herein disclosed.

1. A toilet comprising a toilet bowl, a passage which extends from thebase of the toilet bowl to a drain outlet, and a gate, the gate havingan open position which allows water within the toilet bowl to flow outof the drain outlet by way of the passage and a closed position in whichthe gate retains a continuous body of water within the toilet bowl and aportion of the passage, up to a fill level, the toilet furthercomprising a divider arranged to close off the passage above the filllevel and to extend below the fill level at a location intermediate thetoilet bowl and the water line where the surface of the continuous bodyof water contacts the gate, to form a water trap in use when the gate isin the closed position and water is retained up to the fill level.
 2. Atoilet according to claim 1, wherein the gate comprises a flap having ahinged base and wherein, in the open position, the flap extendshorizontally, or horizontally downwards, from the hinged base, towardsthe drain outlet, to allow water to flow from the toilet bowl throughthe passage over the gate to the drain outlet.
 3. A toilet according toclaim 2, wherein the flap is located within the passage and the divideris located entirely intermediate the flap and the toilet bowl.
 4. Atoilet according to claim 2, wherein the hinged base of the flap islocated underneath the divider, or within the toilet bowl, or betweenthe toilet bowl and the divider, and extends under the divider towardsthe drain outlet.
 5. A toilet according to claim 2, wherein the gatefurther comprises flexible sealing members extending from the flap tothe adjacent walls of the passage.
 6. A toilet according to claim 5,wherein the flap and flexible sealing members are formed as an integralpiece of elastomeric material.
 7. A toilet according to claim 1, whereinthe toilet comprises an adaptor pipe portion and a bowl portion having apassage section, the passage is formed at least in part by the adaptorpipe portion and the said passage section, the adaptor pipe portion andthe bowl portion are attached to each other in an abutting relationship,either or both of the adaptor pipe portion abutting end of the bowlportion and the bowl portion abutting end of the adaptor pipe portioncomprise a recess for receiving the gate, and the base and sides of thegate are sealed into the said recess.
 8. A toilet according to claim 1,wherein the toilet bowl and passage are formed and arranged to provide acontinuous downhill path for water to flow from the toilet bowl throughthe passage to the drain outlet when the gate is in the open position.9. A toilet according to claim 1, wherein the drain outlet is providedbehind the toilet below the base of the toilet bowl and above a floorcontacting base of the toilet.
 10. A toilet according to claim 1,wherein the passage comprises a first passage portion extending underthe divider and a second passage portion extending from the dividertowards the drain outlet, wherein the ceiling of the second passageportion is higher than the fill level so that there is an air spaceabove the body of water in the second passage portion, extending up tothe divider, when the gate is closed and the toilet is filled with waterup to the fill level.
 11. A toilet according to claim 10, wherein thegate extends above the fill level but below the ceiling of the secondpassage portion when the gate is in the closed position.
 12. A toiletaccording to claim 1, wherein the divider is integral to the toiletbowl.
 13. A toilet according to claim 1, wherein the toilet bowlcomprises a rim and a water conduit is provided around the periphery ofthe toilet bowl, near the rim, the water conduit comprising a pluralityof apertures through which water is directed down the sides of the bowlto rinse the sides of the toilet bowl for a period of time and refillthe toilet bowl up to the fill level when the toilet is flushed.
 14. Atoilet according to claim 1, wherein the toilet bowl comprises a rim anda water outlet for supplying flush water to a removable conduit.
 15. Atoilet according to claim 1, wherein the toilet comprises a flushmechanism which is operable to cause the gate to move from the closedposition to the open position for a first period of time followingoperating of a manually operable flush control and then to cause thegate to move from the open position to the closed position.
 16. A toiletaccording to claim 15, wherein the flush mechanism is operable to causewater to flow into the toilet bowl, for example, by way of saidapertures in said water conduit, for a second period of time, which islonger than the first period of time.
 17. A toilet according to claim15, wherein the flush mechanism comprises a hydraulic actuator operableto move the gate between the closed and open position and a hydraulicline operably linked to the manually operable flush control andhydraulic actuator.
 18. A toilet according to claim 17, wherein mainswater is used as the hydraulic fluid to transmit hydrostatic force tothe hydraulic actuator.
 19. A toilet according to claim 17, wherein thehydraulic actuator is a piston cylinder which is mechanically linked tothe gate.
 20. A toilet according to claim 17, wherein the flushmechanism comprises a pressurisable chamber in fluid communication withthe hydraulic line, the pressure within which is changeable by operationof the manually operable flush control.
 21. A toilet according to claim17, wherein a pressure equalising device is provided which is operableto restore pressure in the hydraulic actuator to an equilibrium pressurea period of time after operation of the manually operable flush control.22. A toilet according to claim 21, wherein the pressure equalisingdevice is formed and arranged so that pressure within the hydraulicactuator returns to equilibrium at most slowly for a period of time andthen returns rapidly to equilibrium to return the gate rapidly to theclosed position.
 23. A toilet according to claim 21, wherein thepressure equalising device comprises a slowly leaking member
 24. Atoilet according to claim 21, wherein the pressurisable chamber is achamber within a piston cylinder and the manually operable flush controlis operably linked to the piston cylinder.
 25. A toilet according toclaim 24, wherein the pressurisable chamber is formed in a pistoncylinder between a first piston which is operably linked to the manuallyoperable flush control and a second piston which is biased to compressthe pressurisable chamber wherein the second piston divides thepressurisable chamber from a further chamber within the piston cylinder,the further chamber comprising one or more orifices, wherein the secondpiston is biased to occlude a pressure equalising port of the pistoncylinder, and moveable slowly as a result of water passing slowly out ofthe further chamber through the said one or more orifices, enabling thesecond piston to move slowly to a position where it brings thepressurisable chamber into fluid communication with the pressureequalising port, to enable pressure within the pressurisable chamber torapidly return to the equilibrium pressure.
 26. A toilet according toclaim 15, wherein the flush mechanism is operably linked to a valvewhich is openable for a period of time responsive to operation of theflush control to supply water to the toilet bowl, wherein the mechanismis operable to close the valve responsive to detection by a level sensorthat the level of water within the toilet bowl or passage has reached afill level.
 27. A toilet according to claim 26, wherein the flushmechanism comprises a lever arm having opposite first and second endswith a pivot therebetween, the first end being mechanically attached toa float, functioning as the level sensor, and the second end beingmechanically attached to the said valve.
 28. A toilet comprising atoilet bowl, and a passage which extends from the base of the toiletbowl to an outlet located to the rear of the toilet, the toilet furthercomprising a divider arranged to close off an upper portion of thepassage between the toilet bowl and outlet.
 29. A toilet according toclaim 28, comprising an aperture extending rearwards from the toiletbowl under the divider into a passage, the passage having an interiorsurface which extends higher than the uppermost point of the aperture.30. A toilet according to claim 28, wherein the toilet bowl, passage anddivider are formed as an integrated unit.
 31. A toilet according toclaim 28, wherein the outlet is located below the base of the toiletbowl, above a floor contacting base of the toilet, rearwards of thetoilet bowl.
 32. A kit comprising a toilet according to claim 28,further comprising an adaptor pipe having a gate attached thereto, or afitting for receiving a gate.
 33. A kit according to claim 32, whereinthe kit further comprises a gate and an adaptor pipe having an end, thesaid end of the adaptor pipe and the outlet are adapted to join in anabutting relationship, and either or both of the said end of the adaptorpipe and the outlet comprise a recess for receiving and sealedlyretaining the gate.
 34. A kit according to claim 33, wherein the gatecomprises a flap and flexible sealing members extending from either sideof the flap, formed as a piece of elastomeric material arranged tocooperate with the recess.